1. Field of the Invention
The present invention relates generally to press brake compensators and, more particularly, to devices that indicate the vertical elevation of preselected portions of a die holder member of the press brake compensator.
2. Background of the Prior Art
It is common practice to use press brake compensators between a die and a press bed of a press brake to vary the crown or elevation of the die to obtain consistent bends and angles such that end and mid-portions of a workpiece have the same configurations after the workpiece is bent by a press brake. The press brake compensator is required to compensate for the downward deflection or xe2x80x9cyawningxe2x80x9d in the press bed of the press brake caused by excessive use and operating loads. Further, the design of the press brake will influence workpiece inconsistencies and form an incomplete bend or xe2x80x9cflat spotxe2x80x9d due to deflection of the press bed. The greater the longitudinal dimension of the press bed, the greater the downward deflection in the press bed and the more pronounced the flat spots in the workpiece after operation of the press brake.
It is also common practice to use indicator devices to determine the vertical distance of travel of preselected portions of the press brake compensator when configuring a workpiece. Knowing the distance of travel, provides for a fast set-up of a press brake when adjusted to repeat a configuration for a substantially identical workpiece. Prior art devices utilize indicator pins to indicate the relative adjusted position of a corresponding wedge member. An example of this technique is disclosed in U.S. Pat. No. 4,736,612. The patent teaches the use of horizontal pins to disclose the relative horizontal position of a wedge member. Other prior art devices utilize an indicating gauge in a displacement handle; the handle horizontally moving a wedge member that elevates a die holder member. An example of such a device is disclosed in U.S. Pat. No. 4,898,015.
The problem with this method of indication is that no accurate measurement is taken of the horizontal movement of the indicator pin. Further, no relationship is considered between the horizontal movement of the indicator pin and the vertical displacement of the wedge member. Thus, the press brake compensator cannot be quickly set-up by using measured component displacement to duplicate a prior configuration impressed upon a routine workpiece.
Another method of determining the vertical displacement of a press brake compensator to accomplish a fast set-up, is for a person to physically measure the vertical separation between a die holder member and a press bed engagement member of the press brake compensator. Although the measurement will be accurate, the time spent by the operator to obtain the measurement is excessive and costly which is increased should more than one portion of the press brake compensator need to be measured.
A need exists for a press brake compensator displacement indicator that measures the vertical displacement of a preselected portion of a die holder member of the compensator to provide for the fast set-up of the compensator whenever duplicated bends for multiple workpieces are provided by a press brake.
It is an object of the present invention to provide a displacement indicator device for a press brake compensator. It is an object of the present invention to overcome many of the disadvantages of the prior art.
A principle object of the present invention is to provide a device that indicates the vertical elevation of a preselected portion of a press brake compensator. A feature of the device is an indicator rod positioned at the preselected portion of the press brake compensator; the indicator rod having a circumscribed radial reference mark. Another feature of the device is an indicating scale positioned adjacent to the indicator rod. An advantage of the device is that the vertical elevation of the preselected portion of the press brake compensator is readily determined by a person viewing the reference mark and a corresponding line and number on the scale.
Another object of the present invention is to provide a device that enables a person operating the press brake compensator to easily view a substantial longitudinal portion of the indicator rod. A feature of the device is a first recess or aperture positioned adjacent to a first side wall of a die holder member of the press brake compensator, the aperture extending vertically through the die holder member and snugly receiving the indicator rod. Another feature of the device is an elliptically configured viewing aperture that integrally joins with the first aperture. An advantage of the device is that a person operating the press brake compensator can easily find the reference mark on the indicator rod.
Still another object of the present invention is to provide a device that includes an indicating component that moves vertically in response to the horizontal movement of a wedge portion of the press brake compensator. A feature of the device is a second recess positioned in a side wall of the wedge portion. Another feature of the device is a lifting cam snugly inserted in the second recess. An advantage of the device is that the lifting cam moves the indicator rod vertically as the wedge portion is moved horizontally.
Yet another object of the present invention is to provide a device that includes an indicating component that moves a vertical distance equal to the horizontal distance the wedge portion moves. A feature of the device is an inclined end wall of the lifting cam; the end wall having a slope of forty-five degrees. An advantage of the device is that the indicating scale can be easily calibrated to provide the vertical displacement of the die holder member by aligning the reference mark of the indicator rod with the horizontal lines of the indicating scale when the slope of the wedge portion is not forty-five degrees.
Another object of the present invention is to provide a device having unrestricted engagement between moving components. A feature of the device is the indicator rod having a chamfered bottom wall that is ultimately engaged by a lower edge portion of the lifting cam. An advantage of the device is that the lifting cam easily lifts the indicator rod off a ledge of a press bed engagement member of the press brake compensator.
A further object of the present invention is to provide a device having an indicating range that corresponds to the maximum elevation of the die holder member of the press brake compensator. A feature of the device is an aperture in a first arm member of the press bed engagement member of the press brake compensator. An advantage of the device is that the lifting cam is capable of being moved horizontally through the aperture until the first arm member restricts further movement of the wedge portion thereby preventing further elevation of the corresponding portion of the die holder member.
Briefly, the invention provides a displacement indicator device for a press brake compensator comprising a first recess in a lower wall of a preselected portion of a die holder member of the press brake compensator; an indicator rod snugly inserted into said first recess; a second recess in a side wall of a preselected portion of a wedge portion of the press brake. compensator; a lifting cam snugly inserted into said second recess; means for displacing said indicator rod correspondingly to the displacement of said preselected portion of the wedge portion of the press brake compensator, and means for indicating the quantity of displacement of said preselected portion of the die holder member of the press brake compensator via the displacement of said indicator rod.